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Routing an additional block of existing IP's from another organization

Within the next 6 weeks I will need to route an additional block of IP's that are currently advertised with another AS. We have another reseller that currently has their own AS, /20 IP block, and circuits but will connect to us for bandwidth and ISP services in the near future.

What do you believe is the best migration path for us to route their IP's?

1.For us to advertise their AS on cutnight?

2. or advertise their IP's with our existing AS?

Of course, with either option I will need to coordinate with my upstream ISP's to accept my new advertisements.

Thanks for any thoughts or suggestions!

-JGR

3 REPLIES
Hall of Fame Super Silver

Re: Routing an additional block of existing IP's from another or

Hello JGR,

>> Within the next 6 weeks I will need to route an additional block of IP's that are currently advertised with another AS.

if they are the legimitate owners of these IP address block the advertisement should be originated by their AS number

so I would look for option 1) + update of agreements with your upstream provider so that they add this new client AS number of yours on the accepted routes policy.

Then in the future you can contact RIR (ARIN, RIPE and so on the one that applies to you) to have the ip address block moved to your main AS number and then you can advertise it directly as originated in your main AS number.

Hope to help

Giuseppe

Community Member

Re: Routing an additional block of existing IP's from another or

I see your answer is to advertise their AS with their IP's.

Very good! Thank you!

-JGR

Re: Routing an additional block of existing IP's from another or

Option 1 is less administrative work. Since its eBGP, even a single link will do. You can even give the administration of that domain to one of your junior engineer who are interested in learning BGP. Its flexible as well, if in future they decide to move out (for whatever reason), it will not be that difficult to cut them out. Easier to filter as well.

Option 2 is a lot of work. iBGP design, need RR if not fully meshed. Need to update your RIR. Difficult to filter since its iBGP.

The upstream ISP is only interested on what prefix you are advertising. Unless its a direct peer to them, they are of course interested on the AS as well.

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